By: Wm. Bruce Clevenger, OSU Extension
Ohio is fortunate to host some of the longest running university research on agricultural drainage. One of the first Ohio State University (OSU) and Ohio Agricultural Research and Development Center (OARDC) projects began in 1958 in north central Ohio. Drainage research has been continuous through today with some research factors remaining the same while others evolved with the needs of the agricultural industry.
The major research questions explored by OSU researchers involve the design of surface and subsurface (tile) drainage, tillage systems, crop rotation, water quality, subirrigation, controlled drainage, soil quality, and of course crop yield response. Economic analyses of benefits over costs have been valuable to determine return on investment and payback periods.
Farmers and farmland owners use OSU’s research findings to make land improvements and improve profitability. As more farmland is owned by non-farmers or family members 2-3 generations away from the career of farming, the once inherent and common knowledge of drainage value needs to be taught and shared. Properly designed agricultural drainage can increase crop yields, reduce soil compaction, reduce soil erosion, improve soil quality and can be managed to protect water quality. Understanding Agricultural Drainage AEX 320 (Brown and Ward, 1997) details the principles of drainage that has shaped some of the most productive soils in the Midwest.
Agricultural drainage reduces the year-to-year variability of crop yields compared to having undrained cropland (1962-1980 data from Professor Glen Schwab, Dept of Ag Engineering, Ohio State University). Schwab discovered that a combination of both surface and subsurface showed a benefit cost ration of 1.9 compared to undrained cropland. Based on Schwab’s yield improvement data, the benefit cost analysis indicated that for every dollar put into drainage improvement on this soil, there is a payback of at least $1.20 and $1.90 when growing soybeans and corn, respectively (Brown, 2011 Overholt Drainage School).
More recently, a twenty-five year drainage, tillage and crop rotation study in Northwest Ohio by Ohio State University’s Don Eckert, Randall Reeder and Larry Brown continues today. Corn and soybeans have been grown over the three factors since 1984 on the Hoytville silty clay soil. Crop yields increased because of subsurface drainage by 24%-39% for corn and 13%-46% for soybeans. Crop yields increased because of crop rotation by 11%-23% for corn and 9%-29% for soybeans. Conservation tillage systems are better than plowing and no-till appears to be the best single tillage option. Does drainage pay? Overall, for 25 years, average corn and soybean yield increase due to drainage was 30% (Reeder, 2011, Conservation Tillage Conference, Ada, OH). A 30% corn yield increase equates to taking a 135 bu/acre farm to 175 bu/acre farm. At $7.00 per bushel of corn, that is a $280 gain in gross revenue per year.
Benefit-cost analysis for subsurface drainage by rotation and tillage system for Hoytville silty clay soil (1984-1995) range from 1.7 to 2.2 for corn and 1.3 to 3.1 for soybeans (Brown, 2011 Overholt Drainage School). With today’s corn and soybean prices and an estimated $800 cost per acre of a new drainage system, the benefit:cost ratio is around 4:1 for corn and 3:1 for soybean.
OSU and OARDC are committed to drainage water management research. The demand for food and energy continues to look at the agriculture industry for productive and responsible systems. Ag drainage systems help productivity rise to the current level and will be essential for future advancements.
References:
Brown, L.C., Overholt Drainage School – Annual land improvement and drainage contractor training school. Presentations, field practical, training exercises, and reference materials provided to participants. Ohio State University, Department of Food, Ag and Biological Engineering, Columbus, OH. Miscellaneous Bulletin OAWMGWP No. 1-1/2009. 2011.
Brown, L. C., B. M. Schmitz, M. T. Batte, C. Eppley, G. O. Schwab, R. C. Reeder, and D. J. Eckert. “Historic Drainage, Tillage, Crop Rotation, and Yield Studies on Clay Soils in Ohio.” pp. 456-464 in Drainage in the 21st Century: Food Production and Environment. Proc. 7th International Drainage Symposium. Brown, L. C., ed. Vol. 7:02-98. St. Joseph, MI: ASAE, 1998.
Brown, L.C., A.D. Ward. “Understanding Agricultural Drainage.” OSU Extension Factsheet AEX-320-97. Ohio State University Extension. 1997.
Reeder, R.C., L.C. Brown, E. Ghane. “Twenty-five years of drainage, tillage, crop rotation, and yield studies in northwest Ohio.” Oral presentation at the 2011 Conservation Tillage and Technology Conference. Ada, OH. 2011